Your Structure Sensor and Bridge need to be calibrated before first use to ensure the best possible performance. You only need to calibrate once for every iOS device you use with Bridge.
To calibrate, download the Calibrator app from the app store to your iPhone.
Your Bridge uses the 120º Wide Vision Lens to enhance performance. To calibrate with the Wide Vision Lens, you'll use a checkerboard target. You can either use it on the screen of your computer, or print it out. The checkerboard target can be found here.
Before calibrating, ensure that the Wide Vision Lens is firmly inserted into Bridge. Turn it clockwise until it can no longer be turned.
Open up the Calibrator app, and select "Calibration with Wide Vision Lens". You'll be taken through a series of steps, starting with using the checkerboard target. The final step of calibrator requires that you point your Bridge and Structure Sensor towards a brightly lit and visually complex scene.